Add links to this PR in changelog

Author: edrevo

CHANGELOG.md

@@ -6,7 +6,7 @@
 ### Changed
 
 - Updated to libgit2 [1.6.4](https://github.com/libgit2/libgit2/releases/tag/v1.6.4).
-  [#935](TODO)
+  [#948](https://github.com/rust-lang/git2-rs/pull/948)
 
 ## 0.17.0 - 2023-04-02
 [0.16.1...0.17.0](https://github.com/rust-lang/git2-rs/compare/0.16.1...0.17.0)

libgit2-sys/CHANGELOG.md

@@ -8,7 +8,7 @@
 - Updated to libgit2 [1.6.4](https://github.com/libgit2/libgit2/releases/tag/v1.6.4).
   This brings in many changes, including better SSH host key support on Windows and better SSH host key algorithm negotiation.
   1.6.3 is now the minimum supported version.
-  [#935](TODO)
+  [#948](https://github.com/rust-lang/git2-rs/pull/948)
 
 ## 0.15.0+1.6.3 - 2023-04-02
 [0.14.2...0.15.0](https://github.com/rust-lang/git2-rs/compare/libgit2-sys-0.14.2+1.5.1...libgit2-sys-0.15.0+1.6.3)